Time constraint for the occurrence of uranium deposits and natural nuclear fission reactors in the Paleoproterozoic Franceville Basin (Gabon)

2006 ◽  
Author(s):  
F. Gauthier-Lafaye
Keyword(s):  
Nuclear Fission ◽  
Time Constraint ◽  
Uranium Deposits ◽  
Fission Reactors

Nuclear Fission Reactors

1984 ◽  
Vol 67 (1) ◽  
pp. 183-184 ◽  
Author(s):  
Karl Wirtz
Keyword(s):  
Nuclear Fission ◽  
Fission Reactors

scholarly journals Theoretically and under very special applied conditions a nuclear fission reactor may explode as nuclear bomb

2019 ◽  
Vol 18 ◽  
pp. 121
Author(s):  
J. S. Kondylakis
Keyword(s):  
Nuclear Reactor ◽  
Nuclear Fission ◽  
Reactor Vessel ◽  
Reactor System ◽  
Core Material ◽  
Fission Reactor ◽  
Nuclear Bomb ◽  
Theoretical Approaches ◽  
Supporting Material ◽  
Fission Reactors

This article/presentation describes a theoretical and applied research in nuclear fission reactor systems. It concerns with theoretical approaches and in very special applied cases consideration where a common nuclear fission reactor system may be considered to explode as nuclear bomb. This research gives critical impacts to the design, operation, management and philosophy of nuclear fission reactors systems. It also includes a sensitivity analysis of a particular applied problem concerning the core melting of a nuclear reactor and its deposit to the bottom of reactor vessel. Specifically, in a typical nuclear fission power reactor system of about 1000 MWe, the nuclear core material (corium) in certain cases can be melted and it may deposited in the bottom of nuclear reactor vessel. So, the nuclear criticality conditions are evaluated for a particular example case(s). Assuming an example composition of melted corium of 98 tones of U238 , 1 tone of U235 , 1 tone Pu239 and 25 tones Fe56 (supporting material) in a 5 m diameter of a finite cylindrical nuclear reactor vessel it is found that it may result in nuclear criticality above the unit. This condition corresponds to Supercritical Fast Nuclear Fission Reactor case, which may under certain very special applied conditions to nuclear explode as nuclear bomb.

Improving the Quantification of Deuterium in Zirconium Alloy Atom Probe Tomography Data Using Existing Analysis Methods

2021 ◽  
pp. 1-10
Author(s):  
Megan E. Jones ◽  
Andrew J. London ◽  
Andrew J. Breen ◽  
Paul D. Styman ◽  
Shyam Sikotra ◽  
...  
Keyword(s):  
Hydrogen Embrittlement ◽  
Atom Probe Tomography ◽  
Zirconium Alloys ◽  
Nuclear Fission ◽  
Atom Probe ◽  
Atomic Scale ◽  
Ratio Spectrum ◽  
Alloy Atom ◽  
Fission Reactors ◽  
Tomography Data

Zirconium alloys are common fuel claddings in nuclear fission reactors and are susceptible to the effects of hydrogen embrittlement. There is a need to be able to detect and image hydrogen at the atomic scale to gain the experimental evidence necessary to fully understand hydrogen embrittlement. Through the use of deuterium tracers, atom probe tomography (APT) is able to detect and spatially locate hydrogen at the atomic scale. Previous works have highlighted issues with quantifying deuterium concentrations using APT due to complex peak overlaps in the mass-to-charge-state ratio spectrum between molecular hydrogen and deuterium (H2 and D). In this work, we use new methods to analyze historic and simulated atom probe data, by applying currently available data analysis tools, to optimize solving peak overlaps to improve the quantification of deuterium. This method has been applied to literature data to quantify the deuterium concentrations in a concentration line profile across an α-Zr/deuteride interface.

XPS and XRD Studies of Samples from the Natural Fission Reactors in the Oklo Uranium Deposits

1993 ◽  
Vol 333 ◽  
Author(s):  
S. Sunder ◽  
N.H. Miller ◽  
A.M. Duclos
Keyword(s):  
Oxidation State ◽  
Photoelectron Spectroscopy ◽  
Xrd Analysis ◽  
Binding Energies ◽  
Uranium Deposits ◽  
Xps Spectra ◽  
X Ray ◽  
Two Samples ◽  
Reactor Zone ◽  
Fission Reactors

ABSTRACTMineral samples from the natural fission reactors 10 and 13 in the Oklo uranium deposits were studied using X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) to gain information about the long-term behaviour of UO2 fuel in a geological disposal vault. Two samples from reactor zone 10 (samples # D81N-190292 and D73-88) and one sample from reactor zone 13 (sample # SD37-S2/CD) were analysed. Low-resolution XPS spectra were recorded to determine the major elements present in the ore. High-resolution spectra were recorded to gain information about the chemical state of the elements present in the mineral samples. The samples show low values for the U6+/U4+ ratio. The oxidation state of uranium in these samples is even lower than that in U409. The binding energies of the Pb 4f bands indicate most of the Pb is in the +2 oxidation state in these samples. The C Is band indicates the presence of organic carbon. XRD analysis shows that the main uranium-bearing phase is uraninite and lead is present mainly as galena. The significance of the results for nuclear fuel waste management is discussed.

Nuclear Fission Reactors

1983 ◽  
Author(s):  
Günther Kessler
Keyword(s):  
Nuclear Fission ◽  
Fission Reactors
Sign in / Sign up

Export Citation Format

Share Document